[GRASS5] filtering vector areas

Radim Blazek blazek at itc.it
Sat Jun 19 06:21:32 EDT 2004


I have added 'sides' option to v.to.db, so now it is becomming
SQL exercise.

Radim


On Friday 18 June 2004 13:15, Otto Dassau wrote:
> Dear list,
>
> Currently I try to classify aerial images (30cm resolution) in order to get
> a generalized vector landcover map. Since the SMAP results contain lots of
> small areas. I use r.neighbour (again and again) to filter those areas and
> then convert the results into vector format.
>
> unfortunately those map still contains about 60000 polygons and most of
> them are smaller than maybe 50sqm. How is it possible to delete those
> polygons with different category values? I don't need them on the map?
>
> I would like to dissolve them according to their area size and/or maybe
> their category value for example and put them to one of the larger
> neighbour areas. I tried already the -d parameter in the v.extract module
> established by Radim and Hamish (my last test was on 17.June from CVS) -
> thanks a lot for this help! - but this problem probably can't be solved
> with it.
>
> I hope anyone has an idea to solve this, too ...
>
>   thanks a lot
>    Otto
>
>
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